A suspected drunk driver speeding north on the Loop 101 slammed his Hyundai into the back of an SUV early Saturday morning, killing the three people inside.

Authorities still aren't sure whether the victims in the SUV died from the impact or resulting explosion and fire

Their bodies were severely burned, says Captain Steve Harrison of the Arizona Department of Public Safety. All three were from Arizona, but their identities likely won't be released until later this week.

The Hyundai had been traveling at a high rate of speed at about 1:35 a.m. when it came up on the SUV near the Indian School exit. The investigation was continuing on Monday, but Harrison says it appears that the lower-profile Hyundai car slipped under the bumper of the mid-sized, 1997 Chevrolet SUV and hit the gas tank. Both vehicles rolled as the SUV burst into flame.

The driver of the Hyundai, 32-year-old James Morang of Litchfield Park, was treated and released at a hospital for a broken left hand.